If they are original head bolts they may be too far gone. Nearly all of mine had pitting, thinning of the shank and stretched threads.. This could mean they'll snap when retorqing the head. It happened to me many years ago, broke off flush in the the block and was a real bugger. It can also cause uneven torque over the head as some stretch more than others.
I have a uni torque vrs gasket kit you can have if you want, it has a head, rocker, inlet/exhaust gasket in it with some other things too like stem seals, water pump gasket etc. It's for an L28 though, so not sure if its suitable... Are you L26 or 28